The present invention relates generally to molding devices, and more particularly to devices for shaping heat-formable resilient materials.
In the garment industry, designers of women's apparel often employ "shoulder pads" in dresses, blouses and other tops to give a woman the appearance of somewhat broader, more defined shoulders. Such shoulder pads are normally made of a resilient material such as a fibrous polyester which is heat-molded to have a predetermined radius of curvature that conforms snugly about the shoulder of a woman. The pads are either sewn to the inside of a garment or include fasteners, such as VELCRO (a trademark), to removably fasten the pad to the interior of a garment. The devices for forming such shoulder pads normally include an upright male shaping member situated beneath a female molding member which has a cavity adapted to receive the male shaping member when the female molding member descends to a closed position. The male shaping member and the female molding member are heatable so as to cooperatively shape a piece of heat-formable material which is placed on the male shaping member when the male shaping member and the female molding member are in an open position.
During the production of such shoulder pads, the operator of a pad-forming device places the material to be molded on the top of the male shaping member when the device is in the open position. Because of the small radius of curvature on the male shaping member, the material to be shaped often falls off the male shaping member prior to the closing of the female molding member onto the male shaping member. Thus, operators are tempted, and often do, hold the material to be shaped on the male shaping member until the female molding member begins to descend. This is extremely dangerous as the operator's hands could be crushed between the male shaping member and the female molding member if the operator does not quickly remove his or her hands as the female molding member reaches the male shaping member.
In an effort to increase productivity, some such pad-forming devices include a pair of female molding members and male shaping members so that an operator can insert for shaping in the device two pieces of material, one with each hand. These dual pad-forming devices necessarily occupy both hands of an operator, who must hold the two pieces of material in position for shaping prior to the closing of the male and female members. Thus, if the dual pad-forming device is not automated for the closing of the male shaping member and the female molding member, which automation could be extremely dangerous under these circumstances, the operator must actuate the closing of the male shaping member and the female molding member with a foot pedal or hip. Further, operators will become cognizant of this danger and would hopefully become extremely cautious in carrying out the steps of operating the pad-forming device. Such cautiousness, however, will affect the speed and efficacy with which the operator can carry out his or her responsibilities, thus decreasing productivity.
Another problem associated with pad-forming devices of the type described above is that of the heat-formable material sticking to the cavity surface of the heated female molding member after shaping. When this occurs, the operator must somehow remove the stuck material before continuing the operation of the pad-forming device. Again, this is not only dangerous because the female molding member is heated, but this also decreases productivity because it is time consuming.
To date, no suitable alternative to the above-described method of operation has been put to practice. Molding devices for materials other than those which are resilient have provided elements for holding a workpiece in place prior to the closing of the mold. For example, U.S. Pat. No. 4,686,076 to Dromigny et al discloses a method and apparatus for fabricating, by injection molding, containers having a film coating on their exterior. Dromigny et al provides a male element and a mateable female element disposed in side by side relation, the male element being movable into a cavity of the female element during operation. A horizontal slider is retractably disposed within the female element to hold the film against the male element prior to the closing of the mold. Once the mold is closed, a synthetic material is injected through an injection nozzle provided in the central region of the male element. After the synthetic material sets to form a film-coated container, the male element retracts from the female element to open the mold while the slider advances to eject the film coated container. It is particularly noted that the slider provided in Dromigny et al forcibly holds the film directly against the male element in a vertical position. Further, the Dromigny et al device is constructed so that the film must be maintained in position adjacent to the male element until the slider advances to hold the film against the male element. In this manner, the elements of the Dromigny et al device are not pre-positioned and, therefore, must move in order to get in position to hold the work-piece for molding. Thus, the Dromigny et al device does not solve the above-described problem because an operator's hands would still be in the work area while elements of the device were moving to hold the material.
The above shortcomings make it apparent that improvements which facilitate the safe and efficient operation of pad-forming devices are warranted. Such improvements would be applicable not only to the formation of shoulder pads for women's garments but also to the molding and shaping of other articles made from heat-formable resilient materials. Thus, although the present invention will find its purposes to be furthered primarily with respect to pad-forming devices for molding and shaping shoulder pads for women's garments, it is directed at molding and shaping processes and devices in general.